Balancing arrangement for a fluid handling control body having parts

ABSTRACT

A control body has two pairs of control ports, each pair cooperating with a group of working chambers, and the control ports of each pair being located on opposite sides of a control body. At least one pressure balancing recess is located on either side between two control ports on the same side of the control body, and communicates with the two control ports on the opposite side for balancing the pressure exerted by fluid flowing through the same on the control body.

United States Patent Inventor Appl. N 0. Filed Patented Priority BALANCING ARRAN HANDLING CONTR Karl Eickmann Hayama-machi. Kanagawaken, 2420 Isshiki. Japan June 4, 1969 Aug. 31, 1971 June 7, 1968 Great Britain 12 Claims, 6 Drawing Figs.

US. Cl

CEMENT FOR A FLUID OL BODY HAVING PARTS Primary Examiner-C. J. Husar Attorney-Michael S. Striker a ABSTRACT: A control body has two pairs of control ports,

each pair cooperating with a group of working chambers, and

tro1 ports on the opposite side for balancing the pressure exerted by fluid flowing through the same on the control body.

PATENTED M83] 197% SHEET 1 OF 2 Irw- II in? K N W wk mm E WM K B m 4 3 m 6 6 3 3 w PATENTEDAUGM I97| 3,602 099 SHEET 2 BF 2 BY Wfm BALANCING ARRANGEMENT FOR A FLUID HANDLING CONTROL BODY HAVING PARTS It has been tried to use known systems of fluid pressure balancing recesses also in fluid handling devices with a plurality of working chamber groups. In such fluid handling devices rotor passages lead into the respective working chambers. The workingchamber groups are generally axially distanced from each other and an entrance port and exit port or a plurality thereof, called control ports, are associated to each of the working chamber groups. According to the known fluid pressure balancing systems, fluid pressure balancing recesses were provided laterally of the control ports of the fluid handling devices. It has now been found, that the commonly known and utilized fluid pressure balancing recess systems did not work satisfactory in fluid handling devices with a plurality of working chambers or working chamber groups. It occurred, that at the control body area, between the control ports of the plurality of working chamber groups the rotors rotary control face and the stationary control body face welded with each other and wore off quickly. In searching for the reason of this disadvantage, it has now been found, according to this invention, that it is necessary to provide, influid handling devices with a plurality of working chamber groups, the fluid pressure balancing recesses not only or not laterally of the control ports, but between the two or a plurality of control ports.

CROSS-REFERENCE TO OTHER APPLICATIONS The already known principle of fluid handling balancing recesses on control bodies or rotors of fluid handling devices are described in detail in my US. Pat. Nos. 3,062,151 and 3,136,260, my British Pat. Nos. 909,088 and 909,089, my Australian Pat. Nos. 250,528 and 250,554, my Japanese Pat. No. 3l9,034 and myGerman Pat. No. 1,192,519. According to these patents it is preferred to make the control body of cylindrical configuration and to fit it into the central bore or hub of a rotor of a fluid handling device. Each fluid handling control port of the control bodyis then associated with a pair of fluid pressure balancing recesses on the diametrical side of the control body and these fluid containing fluid pressure balancing recesses are laterally distanced from the associated fluid handling control port, so that the forces of pressure in fluid in the control port and in the thereto associated fluid pressure balancing recesses are of equal strength, but oppositionally directed so that the total of forces of fluid under pressure acting between the rotor and control body are balancing each other to the sum of zero" or about zero." This system of my above-mentioned patents has worked very satisfactorily in operation, as long as the system was applied in fluid handling devices with only one group of working chambers.

However, this system failed under certain conditions, when it was applied to fluid handling devices with a plurality of working chamber groups. In fluid handling devices with a plurality of working chamber groups, especially of working chamber groups with variable working chambers, like radial piston pumps or vane pumps motors or the like, the control ports are axially distanced from each other, because, the working chamber groups are axially located behind each other. The distance between the plurality of working chamber groups and thereby the distance between the plurality of fluid handling control ports cannot be narrowed below a certain minimum, because otherwise no space would remain in the rotor for the plurality of working chamber groups. The distance minimum between the plurality of fluid handling control ports is so large, however, that a heavy force appears in the control ports and in the clearance between the rotor and the control ports to such a large extend, that either the control body deforms under this large load of force resulting from the pressure in the fluid or that the control body is laterally pressed against the rotor and begins to wear, stick or to fuse along the control face of the rotor.

It has been found in accordance with this invention, that all the difliculties can be overcome, if a fluid pressure balancing recess is provided between a pair of fluid handling control ports, on the diametrically oppositional portion of the respective control body or rotor and if the fluid pressure containing balancing recess is associated to at least one fluid handling control port or better, with a pair of fluid handling control ports. Wearing and fusing between the stationary control face and the rotary control face is thereby completely prevented, because the fluid containing fluid pressure balancing recess is located opposite to a pair of control ports, but laterally between the pair of control ports-and provides a force acting on the control body and rotor, which is opposite to the pressure of the pair of fluid handling control ports of equal magnitude of force, so that the forces of the fluid acting between rotor and control body are equalized relatively to each other. At the same time, instead of providing a pair of fluid containing balancing recesses for a fluid handling control port, it is now possible, in accordance with this invention, to provide only one fluid containing balancing recess to a pair of control ports. Thereby the control body becomes less expensive and manufacturing time and cost of the control body is smaller. Yet more important is the fact that if only one fluid containing balancing recess is associated to a pair of control ports, the area of sealing clearances in the neighborhood of fluid ports or fluid containing recesses is reduced and thereby the leakage flow out of the control ports and out of the balancing recesses is reduced in the fluid handling device, because the number of fluid containing balancing recesses and thereby the total flow of fluid thereout is reduced. According to this feature, the volumetric efficiency of fluid handling devices is considerably increased and thereby the total efficiency and power of the fluid handling device is also increased.

According to another embodiment of the invention, a plurality of fluid containing balancing recesses is provided between a plurality of control ports in a fluid handling device with a plurality of working chamber groups. This system can be utilized to balance the fluid force actions between a rotor and a control body in fluid handling devices with a plurality of independent flows of fluid therethrough. In such fluid handling devices with a plurality of flows of fluid through the device, different pressures may act in different flows. Each flow in such a case must be associated with fluid containing balancing recess means in order to counterbalance the action of the fluid handling control ports of the machine. This is done in accordance with this invention by providing for each fluid handling control port a fluid pressure balancing recess not only outwards of therespective control ports, but also each at least one fluid pressure balancing recess relatively inwards to the plurality of control ports. Thereby it is possible to construct fluid handling devices with a plurality of flows through the machine and to achieve a long and useful life of such devices, since wearing and sticking between the rotary control face and the stationary control face of the device is effectively prevented by the means of this embodiment of this invention.

The principle of this invention can be applied to control bodies of the stationary or of the fixed type, as well as to floating control bodies, It can also be provided to rotor means in fluid handling devices in such a way, that the fluid containing balancing recesses are provided in the rotary control face of the rotor of the device. Whether the balancing recesses of this invention are provided in the rotor or in the control body depends upon the preferred design and situation.

BRIEF DESCRIPTION OF THE DRAWINGS For an understanding of the principle of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings:

FIG. 1 shows a longitudinal sectional view of an embodiment of a fluid handling device in accordance with this invention,

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1,

FIG. 3 is a longitudinal sectional view of another embodiment of the invention,

FIG. 4 is a partial cross-sectional view taken along the line IVIV in FIG. 3,

FIG. 5 is a plan view along the line V in FIG. 3, showing a control body of this embodiment of this invention, and

FIG. 6 is a plan view illustrating a modified control body.

In FIG. 1 is shown an embodiment of a fluid handling device, like a pump, motor, compressor or part of an engine, which contains a rotor l and'a control body 2. In rotor 1 are two groups of working chambers provided, namely working chamber groups 7 and 8. The working chambers of working chamber group 8 are distanced in axial direction from the working chambers of the working chamber group 7. Each working chamber group contains a plurality of working chambers. Rotor l is also provided with a central bore or rotor hub. Rotor passages 24 are extending from a working chamber 7 or 8 into the central bore or hub. There could also be a plurality of rotor passages 24 from every working chamber into the rotor central bore. The central bore forms a rotary control face 1a. Inside of the bore in the control portion of control body 2 provided. Control body 2 has an outer surface, which forms a stationary control face. The stationary control face 211 of control body 2 is closely but slidably fitted into the rotary control face of rotor 1, so that leakage between these control faces is kept to a minimum. Rotor 1 is supported in the housing of the machine, which is not shown in the drawings, and the rotor is able to revolve around the axis of the rotor within said housing. Control body 2 is fastened by fastening means 19 to a portion of the housing of the machine. One end of the control body contains the entrance and exit ports 20 and 21. Entrance and exit ports 20 and 21 are sealed relatively to the port housing 23 by the sealing means 22. Fluid passages 9 and 10 extend from the fluid ports or 21 through the control body 2 to the respective fluid handling control port or control ports 3 or 4 or 13 or 14. Symmetrical control ports 3, 4 and 13, 14 are located on opposite sides of control portion. During revolution of the rotor the rotor passages 24 of working chambers 7 and 8 are moving over the respective fluid handling control ports 3 and 13, or 4 and 14. Thus, during operation of the machine, fluid is passed from an entrance port 20 or 21 through a fluid passage 9 or 10 into'a fluid handling control port 3 or 4, or 13 or 14 and therefrom through the respective rotor passages 24 into the respective, expanding working chambers 7 or 8 and thereafter fluid is expelled from the respective contracting working chambers 7 or 8 through the respective rotor passages 24 into the respective fluid handling control ports 3 and 13, or 4 and 14 and therefrom through the respective fluid passage 9 or 10 into and through an exit port 20 or 21. The direction of the flow of fluid may be reversed. According to this invention, however, fluid containing fluid pressure balancing recesses 5 and 6 are provided on control body 2 between the respective fluid handling control ports 3 and 4, or 13 and 14.

For a better understanding of the invention certain parts of the stationary control face of control body 2 shall now be defined as follows:

The vertical axial plane through the control body 2 of FIG. 2 shall divide this control body into two portions, the left portion and the right portion. The left portion of control body 2, which is visible in the view upon it, in FIG. 1 shall hereafter be called the front are 11 of control body 2, and the right side of FIG. 2 shall be called the back are of control body 2.

In the front are of control body 2 are the control ports 3 and 4 provided. On the back arc of control body 2 are the control ports 13 and 14 provided. During a revolution of rotor 1 the respective rotor passages 24 of the working chambers 7 are moving during about half of a revolution over the fluid handling control port 3 and, during the other half of the revolution over the fluid handling control port 13. The rotor passages 24, which are associated with respective fluid handling working chambers 8 are moving during a revolution of rotor 1 over control port 4 and thereafter over control port 14. About half of a revolution the respective rotor passages move over the fluid handling control port 4 and during the other half of the revolution over the control port 14. If fluid under high pressure is in control ports 3 and 4, then the control body 2 would be pressed with its back arc against the rotary control face la of rotor 1 and it would cause wear thereon.

In order to prevent such wearing between the rotor control face 1a of rotor l and the stationary control face 2a of control body 2, the fluid containing fluid pressure balancing recess 6 is provided on the back arc of control body 2 and between the control ports 13 and 14 of control body 2. However, the fluid is supplied into the fluid containing balancing recess 6 not out of control ports 13 and 14, but out of control ports 3 and 4. For this purpose the communication passages 15 and 16 are extending from the fluid handling control ports 3 and 4, respectively, into the common fluid containing fluid pressure balancing recess 6 on the back arc of control body 2. The size of fluid containing balancing recess 6 is so dimensioned, that the force of pressure of fluid in it substantially balances the force of pressure of fluid handling control ports 3 and 4 in such a way that the forces in the fluid containing balancing recess 6 are substantially equal to the forces of fluid handling control ports 3 and 4, but opposite thereto. For the dimensioning of the fluid containing balancing recess 6 it is also necessary to consider the action of forces of fluid under pressure in the clearances between the rotary controlface 1a of rotor 1 and the stationary control face 2a of control body 2 in the proximity of the fluid handling control ports and of the fluid containing balancing recesses. These forces of these fluid films are of relatively large magnitude and they must be considered under all circumstances, since in the proximity of high pressure recesses, the pressure in the fluid films is almost as high as in the adjacent high pressure recesses. It gradually decreases to the low pressure in the proximity of the low pressure recesses or of the nonpressurized areas of the machine. Fluid passages 15 and 16 may be provided through the control body 2 or along the surface 2a thereof. When fluid passages 15 and 16 are provided in the outer surface 2a of control body 2, the forces of fluid therein push the control body 2 into the opposite direction.

In order to counterbalance such action the communication recess extensions and 116 may be provided on the oppositional side or arc of control body 2. 'Thus, if high pressure is provided in the fluid handling control ports 3 and'4, the control body 2 is floating in an equalized fluid film within the rotor bore 1a of rotor l, or the rotor l is floating on an equalized fluid film around the control body 2. If, on the contrary, high pressure fluid is in control port 13 and 14 on the back are of control body 2, then this fluid flows through communication passages 17 and 18 into the fluid containing fluid pressure balancing recess 5 in the front arc of control body 2. Fluid containing fluid pressure balancing recess 5 is located between the fluid handling control ports 3 and 4, but thereby on the diametrically opposite arc of the control body, respective to the fluid handling control ports 13 and 14. Equalizing forces of fluid, which might act out of communication recesses 17 and 18 of the recess extensions 117 and 118 may be provided for on the opposite arc of control body 2. Instead of providing the fluid containing fluid pressure balancing recesses 5, 6 in control body 2, corresponding recesses may also be provided in the rotor 1. The provision of the fluid containing fluid pressure balancing recesses 5 and 6 between the respective control ports 3 and 4, and 13 and 14, respectively, of the embodiment of FIGS. 1 and 2, has a number of advantages. First of all the rotor and control body 2 are, relative to each other, almost completely balanced, so that they float relative to each other on a fluid film in the clearance between the stationary control face 2a and the rotary control face 10. One sided forces of pressure in fluid are counterbalancing each other by opposite, but substantially equal forces of fluid under pressure. Another feature is, that the space is effectively used so that a compact short machine can be built, since the fluid containing fluid pressure balancing recesses are not located outwardly of the fluid handling control ports, but located between them. Another feature, is that the control body suffers almost no deformation, since the control ports and the counteracting, associated fluid containing fluid pressure balancing recesses are relatively close together. This assures, that the axis of the control body or the axis of the rotor can not be deformed under high pressure of fluid in the control ports, fluid containing fluid pressure balancing recesses or in the clearance between the rotary and stationary control faces. Another feature of this embodiment is, that the leakages of the fluid film between stationary and rotary control faces of the machine are reduced to a minimum, because each fluid handling control port is not associated with a pair of fluid containing balancing recesses is associated, but on the contrary, with each a pair of fluid handling control ports, only one fluid containing balancing recess is associated. Consequently, there are only a few areas in the fluid film, where leakage from high pressure areas to low pressure areas occurs.

In another embodiment of this invention shown in FIG. 3-5, the working chambers of the working chamber groups 37 receive one flow of fluid through fluid handling control port 33 and. discharge flow of fluid through' the diametrically located fluid handling control port 43. The flow of fluid may also be reversed. Another flow of fluid flows through control port 34 into the respective fluid handling chambers 38 of the working chamber group 38 and discharged therefrom through the respective Fluid handling control ports 44. The direction of this flow of fluid may also be reversed. The rotor passages 24 functions as those in FIG. 1. Rotor 31 may be similar to rotor l of FIG. 1. In the control body 32 according to FIG. 35 a plurality of fluid containing fluid pressure balancing recesses are provided between respective fluid handling control ports. In this embodiment, the fluid containing balancing recesses 66 and 75 are provided between the fluid handling control ports 33 and34. On the diametrically opposite arc of control body 32 are the fluid containing fluid pressure balancing recesses 65 and 56 provided between the fluid handling control ports 43 and 44. Since the different flows of fluid, which flow through the'working chambers of'working chamber group 37 and 38 may have with different pressure, it is suitable, in accordance with this embodiment of the invention to provide a complete pair of fluid containing fluid pressure balancing recesses for each respective fluid handling control port. Therefore fluid handling control port 33 communicates through communication conduit recesses 67 and 68 with fluid containing fluid pressure balancing recesses 55 and 56. Fluid handling control port 34 communicates through communication recesses 77 and 78 with the fluid containing fluid pressure balancing recesses 65 and 66.

Fluid handling control port 43 communicates through communication passages, bores or recesses 47 and 48 with fluid containing fluid pressure balancing recesses 65 and 66. Fluid handling control port 44 communicates through communication recesses 57 and 58 with fluid containing fluid pressure balancing recesses 75 and 76.- Communication recess extensions for balancing the forces of fluid of other recesses may also be provided and they are shown in FIGS. 3 and 5 as communication recess extensions 49, 69, 59, 79. To each fluid handling control port 33 and 34 on the front arc of the control body 32 corresponds a pair of fluid containing fluid pressure balancing recesses 55, 56 or 65, 66 in the back arc of control body 32. Each one of a pair of balancing recesses is axially distanced and located between the respective associated fluid handling control ports. Accordingly, each fluid handling control port 43 and 44 in the back are of control body 2, is associated with a pair of fluid containing fluid pressure balancingrecesses 55, 56 and 75, 76 in the front control body 2.

Thus, the complete floating on a fluid film under pressure, between the rotary and stationary control faces, of either the control body 32 in rotor 31, or of rotor 31 around control body 32', is assured. At the same time deformation of the axis of the control body 32 or of the rotor v31 is prevented, since fluid pressure balancing recesses are provided on the opposite arcs of the control body between each pair of control ports. The embodiment of FIG. 3 to 5 therefore makes a machine or fluid handling device suitable for high pressure fluid and thereby of a large power at high efficiency.

In the plan view FIG. 5 upon the control body 32, it is clearly visible, how the communication passages or recesses can be set, by way of example, in order to connect each pair of balancing recesses, with the respective: associated fluid handling control port. L

Another embodiment of a control body with fluid pressure balancing recesses is shown in FIG. 6 :in a similar view as is FIG. 5. Control body 232 of FIG. 6 can be applied in the machine of FIG. 3 instead of control body 32 thereof.

The specific and novelfeature of the control body of FIG. 6, reside in the configuration and specific location of the fluid containing pressurebalancing recesses. Balancing recess 253 is by communication means 257 connected with to fluid handling port 233. Balancing recess 254 is by communication means 260 connected with fluid handling port 234. Balancing recess 251i is by communication means 258 connected with fluid handling control port 243, and balancing recesses 255 and 256 due connected by communication means 259 with each other and by handling control port 244. Instead of associating recesses 253 and 254, it is possible to associate recess 251 and recess pair 255 and 256 with a respective fluid port pair of vice versa.

While control body 32 of FIG. 3 includes fluid containing balancing recesses, for example 55, 65, 66, and 67 axially outwards of fluid-port pair 33, 43, 34 and 44, the novel control body 232 of FIG. 6 contains all fluid containing fluid pressure balancing recesses axially in between the control ports. The number of recesses and thereby the total of the sum of leakage flows is hereby effectively decreased. That in turn increases the volumetric and total efficiency of the fluid handling device. Recesses 255, 256 may embrace recess 251, so that the resultant fluid forces of recess pair 255, 256 may have the same location, as that of recess 251. The sum of the sectional area of recess pair 255, 256 be equal to that of recess 251. Other configurations and locations are possible, but the above described can be considered as most economical.

While the invention is described with reference to some embodiments, it should be understood, that it is not restricted to the embodiments, which are shown in the drawings. It is possible to modify the details of the invention, without departing from the scope of this invention and it is therefore intended that the claims shall cover whatever patentable novelty resides in the invention.

What is claimed is:

1. In a fluid handling device, in combination, a balancing arrangement for a control body having ports, comprising rotor means having a plurality of working chambers, a rotary control surface, and passages connecting said working chambers with said rotary control surface; and a control body having a stationary control surface cooperating with said rotary control surface, at lease two control ports in said stationary control surface on one side of said control body, and fluid passages connected with said control ports so that fluid flows through said control ports, passages, and working chambers, said control body having in said stationary control surface thereof at least one pressure balancing recess means on the other side of said control body diametrically opposite said two control ports in the direction of rotation of said rotor means, and intermediate said two control ports in axial direction of said rotor means, so that fluid in said pressure balancing recess means and in said control ports produces opposite pressure forces acting on said rotary control surface and on said control body for balancing the same.

2. Balancing arrangement as claimed in claim I wherein said stationary and rotary control surfaces are cylindrical and have substantially the same diameter; wherein said pressure balancing recess means and said control ports are located in diametrically opposite arc portions of said stationary control surface; and wherein said pressure balancing recess means is spaced equal axial distances from said control ports.

3. Balancing arrangement as claimed in claim 1 wherein said rotor means has two axially spaced groups of circumferentially spaced working chambers communicating through said passages with said two control ports, respectively; wherein said control body has on said other side two other control ports diametrically opposite said control ports and aligned with the same in circumferential direction, said other control ports also communicating through said passages with said two groups of working chambers, respectively; and wherein said control body has on said one side in said stationary control surface an other pressure balancing recess means between said control ports on said one side and diametrically opposite said pressure balancing recess means circumferentially aligned with the same.

4. Balancing arrangement as claimed in claim 1 comprising conduit means for connecting at least one of said control ports with said pressure balancing recess means.

5. Balancing arrangement as claimed in claim 1 wherein said control body has conduit means for connecting at least one of said control ports with said pressure balancing recess means.

6. Balancing arrangement as claimed in claim 1 wherein said balancing recess means include a plurality of pressure balancing recesses on said other side of said control body and intermediate said two control ports in axial direction of said rotor.

7. Balancing arrangement as claimed in claim 1 wherein said rotor means has two axially spaced groups of circum ferentially spaced working chambers communicating through said passages with said two control ports, respectively; wherein said control body has on said other side two other control ports diametrically opposite said control ports and aligned with the same in circumferential direction, said other control ports also communicating through said passages with said two groups of working chambers, respectively; wherein said control body has on said one side in said stationary control surface an other pressure balancing recess means between said control ports on said one side diametrically opposite said pressure, balancing recess means circumferentially aligned with the same; and wherein each of said pressure balancing recess means includes at least two pressure balancing recesses disposed so that pairs of pressure balancing recesses located diametrically opposite each other are aligned in circumferential direction.

8. Balancing arrangement as claimed in claim 1 wherein the circumferential length of said pressure balancing recess means is equal to the circumferential length of said control ports; and

wherein the axial width of said pressure balancing recess is sub: tntially equal to the combined axial width of said control ports.

9. In a fluid handling device such as a pump, motor, compressor, or engine in combination, a rotor means provided with a plurality of groups of fluid handling working chambers therein and with a rotary control face thereon; and a control body including passages for passing fluid through respective control ports into said working chambers in said rotor means and out of the same, said control body having a stationary control face associated with said rotary control face of said rotor means; characterized in that a pair of control ports associated with each group of working chambers is provided in said control body; and that at least a pair of fluid containing fluid pzessure balancing recesses is associated with and communicates with each of said control ports of said control body, each pair of pressure balancing recesses being located diametrically opposite the respective associated control ports, but relatively between the same.

10 The device of claim 9 wherein at least one of said pressure balancing recesses is located outward of said control ports, and another pressure balancing recess is located relativelf' between two of said control ports.

1 In a fluid handling device such as a pump, motor, compressor, or engine in combination, a rotor means provided with a plurality of groups of fluid handling working chambers therein and with a rotary control face thereon; and a control body including passages for passing fluid through respective control ports into said working chambers in said rotor means and out of the same, said control body having a stationary control face associated with said rotary control face of said rotor means; characterized in that a pair of fluid containing fluid pressure balancing recesses is associated with a pair of fluid handling control ports of one group of working chambers and another pair of fluid containing fluid pressure balancing recesses is associated with another pair of fluid handling control ports of another group of working chambers; and that some of said pressure balancing recesses are located between said control ports in said control body; and that cooperating pressure balancing recesses and control ports are located on diametrically opposite portions of said control body, but relatively between the same.

12. Balancing arrangement as claimed in claim 12, wherein said rotor means has two axially spaced groups of circumferentially spaced working chambers communicating through said passages with said two control ports, respectively; wherein said pressure balancing recess means is a single pressure balancing recess on said other side; wherein said control body has on said other side two other control ports diametrically opposite said control ports and aligned with the same in circumferential direction, said other control ports also communicating through said passages with said two groups of working chambers, respectively; wherein said control body has on said one side in said stationary control surface a single pressure balancing recess between said control ports on said one side and diametrically opposite said single pressure balancing recess circumferentially aligned with the same; and comprising first conduit means connecting at least one of said control ports on said one side with said single pressure balancing recess on said other side, and second conduit means connecting at least one of said control ports on said other side with said single pressure balancing recess on said one side. 

1. In a fluid handling device, in combination, a balancing arrangement for a control body having ports, comprising rotor means having a plurality of working chambers, a rotary control surface, and passages connecting said working chambers with said rotary control surface; and a control body having a stationary control surface cooperating with said rotary control surface, at lease two control ports in said stationary control surface on one side of said control body, and fluid passages connected with said control ports so that fluid flows through said control ports, passages, and working chambers, said control body having in said stationary control surface thereof at least one pressure balancing recess means on the other side of said control body diametrically opposite said two control ports in the direction of rotation of said rotor means, and intermediate said two control ports in axial direction of said rotor means, so that fluid in said pressure balancing recess means and in said control ports produces opposite pressure forces acting on said rotary control surface and on said control body for balancing the same.
 2. Balancing arrangement as claimed in claim 1 wherein said stationary and rotary control surfaces are cylindrical and have substantially the same diameter; wherein said pressure balancing recess means and said control ports are located in diametrically opposite arc portions of said stationary control surface; and wherein said pressure balancing recess means is spaced equal axial distances from said control ports.
 3. Balancing arrangement as claimed in claim 1 wherein said rotor means has two axially spaced groups of circumferentially spaced working chambers communicating through said passages with said two control ports, respectively; wherein said control body has on said other side two other control ports diametrically opposite said control ports and aligned with the same in circumferential direction, said other control ports also communicating through said passages with said two groups of working chambers, respectively; and wherein said control body has on said one side in said stationary control surface an other pressure balancing recess means between said control ports on said one side and diametrically opposite said pressure balancing recess means circumferentially aligned with the same.
 4. Balancing arrangement as claimed in claim 1 comprising conduit means for connecting at least one of said control ports with said pressure balancing recess means.
 5. Balancing arrangement as claimed in claim 1 wherein said control boDy has conduit means for connecting at least one of said control ports with said pressure balancing recess means.
 6. Balancing arrangement as claimed in claim 1 wherein said balancing recess means include a plurality of pressure balancing recesses on said other side of said control body and intermediate said two control ports in axial direction of said rotor.
 7. Balancing arrangement as claimed in claim 1 wherein said rotor means has two axially spaced groups of circumferentially spaced working chambers communicating through said passages with said two control ports, respectively; wherein said control body has on said other side two other control ports diametrically opposite said control ports and aligned with the same in circumferential direction, said other control ports also communicating through said passages with said two groups of working chambers, respectively; wherein said control body has on said one side in said stationary control surface an other pressure balancing recess means between said control ports on said one side diametrically opposite said pressure, balancing recess means circumferentially aligned with the same; and wherein each of said pressure balancing recess means includes at least two pressure balancing recesses disposed so that pairs of pressure balancing recesses located diametrically opposite each other are aligned in circumferential direction.
 8. Balancing arrangement as claimed in claim 1 wherein the circumferential length of said pressure balancing recess means is equal to the circumferential length of said control ports; and wherein the axial width of said pressure balancing recess is substantially equal to the combined axial width of said control ports.
 9. In a fluid handling device such as a pump, motor, compressor, or engine in combination, a rotor means provided with a plurality of groups of fluid handling working chambers therein and with a rotary control face thereon; and a control body including passages for passing fluid through respective control ports into said working chambers in said rotor means and out of the same, said control body having a stationary control face associated with said rotary control face of said rotor means; characterized in that a pair of control ports associated with each group of working chambers is provided in said control body; and that at least a pair of fluid containing fluid pressure balancing recesses is associated with and communicates with each of said control ports of said control body, each pair of pressure balancing recesses being located diametrically opposite the respective associated control ports, but relatively between the same. 10 The device of claim 9 wherein at least one of said pressure balancing recesses is located outward of said control ports, and another pressure balancing recess is located relatively between two of said control ports.
 11. In a fluid handling device such as a pump, motor, compressor, or engine in combination, a rotor means provided with a plurality of groups of fluid handling working chambers therein and with a rotary control face thereon; and a control body including passages for passing fluid through respective control ports into said working chambers in said rotor means and out of the same, said control body having a stationary control face associated with said rotary control face of said rotor means; characterized in that a pair of fluid containing fluid pressure balancing recesses is associated with a pair of fluid handling control ports of one group of working chambers and another pair of fluid containing fluid pressure balancing recesses is associated with another pair of fluid handling control ports of another group of working chambers; and that some of said pressure balancing recesses are located between said control ports in said control body; and that cooperating pressure balancing recesses and control ports are located on diametrically opposite portions of said control body, but relatively between the same.
 12. Balancing arrangement as cLaimed in claim 12, wherein said rotor means has two axially spaced groups of circumferentially spaced working chambers communicating through said passages with said two control ports, respectively; wherein said pressure balancing recess means is a single pressure balancing recess on said other side; wherein said control body has on said other side two other control ports diametrically opposite said control ports and aligned with the same in circumferential direction, said other control ports also communicating through said passages with said two groups of working chambers, respectively; wherein said control body has on said one side in said stationary control surface a single pressure balancing recess between said control ports on said one side and diametrically opposite said single pressure balancing recess circumferentially aligned with the same; and comprising first conduit means connecting at least one of said control ports on said one side with said single pressure balancing recess on said other side, and second conduit means connecting at least one of said control ports on said other side with said single pressure balancing recess on said one side. 